Pokémon: Omega Ruby & Alpha Sapphire Guide

Finishing Up in Mossdeep

As you exit ontop Mossdeep City, you’ll suddenly feel the ground shake violently; to the south, you can see a bright viridian beam shoot up into the sky from around Route 128. Take particular note of the area shown during the cutscene; you’ll go there eventually.

Steven will take you to his place and explain what’s going on: that, apparently, the ancient Pokémon hidden beneath Route 128 has been unsealed by Team Aqua/Magma. He’ll give you HM07 (Dive) to help you on your way. You’ll also get the Devon Scuba Gear to allow you to be underwater.